Alkyl-substituted polyaromatic

Transition-metal sulfide (TMS) catalysts play an important role in the petroleum industry. TMS are unique catalysts for the removal of heteroatoms (N, S, 0) in the presence of large amovmts of hydrogen (3). Hydrodesulfiirization (HDS) of petroleum feedstocks are commercially achieved with M0S2 or WS2 supported on alumina and promoted by Co or Ni, (3,4). Co-promoted catalysts are mainly used for HDS, whereas Ni-promoted catalysts are superior for HDN and hydrogenation reactions (5). Catal3rsts currently employed need to be improved to satisfy the imminent restrictions that require the removal of the most refractory species, mainly alkyl-substituted polyaromatic thiophenes. 

Polyaromatic hydrocarbons (PAHs) and alkyl-substituted PAHs were extracted, isolated, and analyzed from Hinkel Reservoir sediments using a variation of the procedure of Furlong et al. (1995). Variations include the addition of a silica column cleanup step following the gel permeation chromatography cleanup step and the use of selected ion monitoring (SIM) MS to reduce chemical interferences and improve detection limits. 

Another growing technique is super-critical fluid chromatography. Recent references to soil analysis include the following applications aliphatic hydrocarbons, polyaromatic hydrocarbons, polychlorobiphenyls, dioxins, alkyl and aryl phosphates, chloro, organophosphorus, triazine, substituted urea, phenoxy acetic acid, Dacthal herbicides and insecticides and mixtures of herbicides and pesticides and mixtures of organic compounds. 

---